Watch-pivot



(No Model.)

G. E. MONFORT. WATCH PIVOT.

No. 410,173. Patented Sept. 3, 1889.

WITNESSES I fw 6. 44M 4 W X Attorney N. PETERS. MID-Lithographer, WuIMflovl, D C

UNITED STATES PATENT ()FFICE.

CHARLES E. MONFORT, OF UTICA, MICHIGAN.

WATCH-PIVOT.

SPECIFICATION forming part of Letters Patent No. 410,173, dated September 3, 1889. Application filed January 3, 1888. Serial No. 259,592. (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. MONFORT, a citizen of the United States, residing at 'Utiea, county of Macomb, State of Michigan, have invented a certain new and useful Improvement in Pivots for IVatches; and I declare the following to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention consists of the improvement herein described, and more particularly pointed out in the claims.

In the drawings, Figure 1 represents an enlarged view of the balance-wheel staff of a watch. Fig. 2 represents the same in longitudinal section. Fig. 3 represents a variation in which the removable pivot screws onto the shaft instead of into the shaft.

It is well known among watch-makers that one of the most difficult operations to properly perform is the introduction of a new pivot when the original has been broken. It has usually required the watch-maker to draw the temper from the steel shaft or staff to soften it; then it has been necessary to drill the end of the shaft and to introduce therein a new pivot which either before or after introduction has been properly turned and dressed.

It is the purpose of my invention to facilitate the renewalof abroken or deranged pivotof this character. To this end I make the staff or shaft with an orifice in each of its ends, the said orifices being screw-tapped. I then provide the shaft with pivots, which are screw-cut to enter the said screw-tapped orifice.

In the drawings, A represents the balancestaff of a watch. B represents its pivots. These pivots are screw-cut at b to engage threads at Z) on the shaft. 1 would have it understood that this pivot may be screw-cut to enter a tapped orifice on the shaft, or it may be in the form of a screw-tapped cup, as shown in Fig. 3, to screw upon. the end of the shaft. So, also, it may or may not be provided with an angular head I) to facilitate grasping the same with a wrench or with pliers.

I do not limit myself wholly to the use of this invention in watches; but it is applicable in clocks and in other localities where fine journal-pivots are apt to become broken.

It is well known to watch-makers that unless a pivot is perfectly true the whole operation of the watch is impaired, and should one become bent, broken, or distorted this invention enables an ordinary workman to remove the broken or injured pivot and to replace it with one which is perfectly true, which leaves the watch in this respect as good as new, and enables the work to be done by an ordinary hand instead of requiring, as is frequently the case, that the watch be sent at large expense to a factory or to some competent workman. It also obviates the necessity of heating the shaft to draw the temper, and thereby obviates warping, which frequently results from this process.

I am aware of the device patented to Simon, October 24, 1871, No.120,335. Simons device, however, is simply a means for repairing a broken pivot by first turning a tenon on the end of the broken shaft and then slipping thereon a separate pivot-cap. It is manifest, however, that the broken shaft must first be heated to draw its temper before the tenon can be turned on it, and this heating is apt to ruin the shaft or stem. So, also, the cap being simply slipped on the tenon is very apt to fit more or less loosely, and the slightest play would of course impair the operation of the watch mechanism. My device, how ever, is not designed as a means for repairing the broken pivots of ordinary stems; but

.I propose constructing the stem in the first instance with the said removable pivots and engaging the pivot-s with the stems by screwthreaded connections, so that the fit may be perfect, and so that there maybe absolutely no play between the parts. So, again, should it be desirable that the new stem should be slightly longer than the old one, to compensate for wear at the pivot or for any other reason the screw-threaded connection forms a means for producing any desired adjustment of the length. So, also, should the end of either pivot become worn the screw-threaded engagement of the pivots affords means whereby both pivots may be slightly, so as to compensate for the wear without disturbing the position of the other elements on the shaft wiseadjustable balance-staff, iubstantially as described.

3. An extensible balance-st-afi consisting of a shaft provided at one or both of its ends with a pivot engaged therewith by a screwthread, substantially as described.

In testimony whereof I sign this specification in the presence of two witnesses.

' CHARLES E. MONFORT. Witnesses:

M. B. ODoeHERTY, SAMUEL E. THOMAS. 

